Significance of immunoregulatory T cells in different stages of breast cancer patients.

Evidence from breast cancer patients suggests that increased T suppressor cells activity may be associated with poor immune responses to tumor antigens and contribute to immune dysfunction. It was demonstrated that these suppressor cells could be CD4+CD25+ T regulatory cells (Treg cells). FOXP3, a forkhead/winged helix transcription factor was found to be essential for the development and control of Tregs. It has been used recently as a biomarker and a prognostic factor for malignant human tumors. The aim of this study was to evaluate the significance of CD4+CD25+ Treg cells changes in the peripheral blood in relation to FOXP3 expression in different stages of breast cancer patients. The present study included 30 female patients of breast cancer (group A) and 10 female healthy volunteers as control (group B). In group A, ten patients (33.3%) were in stage I, ten patients in stage II (33.3%) and ten patients in stage III-IV (33.3%). Serum level of tumour marker (CA15-3) was measured by ELISA. Determination of the percent expression of CD4+ CD25+ of total CD4+ T cells and FOXP3+ Treg cells was done by flowcytometry. The serum level of CA15-3 was significantly higher in group (A) than in group (B) (P = 0.001). Also, CA15-3 was significantly increased as the stage of the disease increased. The percentages of both CD4+ CD25+ and FOXP3+ Tregs in the peripheral blood were significantly higher in group (A) than in group (B) (P = 0.001) and they increased significantly as the stage of the disease increased. A significant positive correlation was found between the percentage of CD4+ CD25+ Tregs and FOXP3+ Tregs in the peripheral blood (P = 0.0649, r = 0.001) and with serum level of CA15-3 (P = 0.880, r = 0.001). It was concluded that CD4+CD25+ FOXP3+Tregs may be responsible for immune suppression in breast cancer. They are also valuable for assessing disease prognosis. This finding can be of utmost significance under the light of Tregs being implicated in carcinogenesis and ongoing efforts towards the development of anticancer approaches specifically inhibiting the expression and/or function of Foxp3 by tumor-associated Tregs.